few lines of jquery which will make a css based "flyout" nav acessible via the keyboard and work in ie6.

accessibleFlyoutNav

$(document).ready(function() {
	$('#navPrimary').children().focusin(function() { $(this).addClass('accessibleHover'); })
	$('#navPrimary').children().focusout(function() { $(this).removeClass('accessibleHover'); })
});

Adding the response here for posterity.

You'd have a lot of focusout handlers

 $('#navPrimary').children().focusin(function() {
   // You would re-add the `focusout` handler every time `focusin` was called.
   $(this).addClass('accessibleHover').focusout(function() {
     $(this).removeClass('accessibleHover');
   });
 });